Currently, smart terminal equipment is used more and more, including various slide-type mobile phones, and clamshell-type mobile phones, etc. How to detect an opened state or a closed state of terminal equipment must be taken into consideration in the design of smart terminal equipment.
Qwerty keyboard layout is used more and more in the smart terminal equipment, and many touch keys may be provided above the Qwerty, such as a multi-media control key (play, forward, and backward, etc.), and a volume control key, etc.